Many industries in which finished products are assembled from components have, over the past decade, made use of robotic assembly machines. The use of robots has been prevalent in a wide variety of applications ranging from automobile assembly to the assembly of electronic circuit boards and many other consumer products. In general, robotic assembly machines have traditionally been very expensive and heavy because of the precision, accuracy, and continuous duty cycle requirements placed upon them. Many robotic assembly machines have a cantilevered arm that can swing around to pick up components and then swing back to install the components on the product being assembled. Some machines are "blind" in that they are programmed to move in a certain precise way without any feedback regarding the location of the components they are working on. With these machines, both their precision and the precision and placement of components parts and of the products being assembled must be high and carefully controlled. Otherwise, the robot will miss a component or misplace the component on the finished product.
The need for inexpensive, yet accurate and reliable robot assembly machines is the result of ordinary economics. When American manufacturers assemble products, they generally compete in a world market that often has an effective wage rate of less than $5.00 per day, including fringe benefits and overhead. Thus, in some instances, it may be more economical to hire several third world workers to do the job of one robot. However, if such robots could be manufactured relatively inexpensively, yet with operation precision, accuracy, speed and reliability akin to the performance of more expensive robots, many assembly markets where robots have not been feasible would become open to use of such robots. In general, a machine cost of $20,000 or less would be considered a good target for a general purpose assembly robot.
Thus, it is seen that a continued need exists for an inexpensive machines with imprecise construction and low weight requirements yet that performs assembly with high precision and high speed. It is to the provision of such a robotic assembly machine that this invention is primarily directed, however, the present invention also applies to any type of application such as machine operations, machining and other controlled motion processes.